Muay Thai fighters can come in all shapes and sizes, a lesson a few gym trainers learned the hard way when Germaine Yeap stepped into their ring. After posing as a timid wannabe fighter, Yeap destroyed her opponents in a way they never saw coming.

The video (below) proves the age-old idiom - don't judge a book (in this case: girl) by its cover.

Germaine Yeap is one of the better known female Muay Thai fighters. After studying the fighting style at the University of Warwick, Yeap soon climbed to the top of her class, eventually reaching wide acclaim and competing internationally.

She's appeared in a number of viral videos that feature her fighting skills, ranging from prank videos to public service announcements. Yeap, along with athletes like Ronda Rousey, are part of the growing class of female fighters that continue to break down gender barriers to the world of martial arts.